Synergistic effects: a common theme in mixed‐species litter decomposition

Abstract

Litter decomposition plays a key role in ecosystem nutrients cycling, yet, to date science is lacking a comprehensive understanding of the non-additive effect in mixing litter decomposition.In order to fill that gap, we compiled 69 individual studies for the purpose of performing two sub-meta-analyses on the non-additive effect.Our results show that a significantly synergistic effect occurs at global scale with the average increase by 2-4% in litter mixture decomposition; In particular, low-quality litter in mixture shows a significantly synergistic effect, while no significant change is observed with high-quality species. Additionally, the synergistic effect turns into the antagonistic effect when soil fauna is absent or litter decomposition enters into humus-near stage. In contrast to temperate and tropical areas, studies in frigid area also show a significantly antagonistic effect.Our meta-analysis provides a systematic evaluation of the non-additive effect in decomposition mixed litters, which is critical for understanding and improving the carbon forecasts and nutrient dynamics.

Global responses of fine root biomass and traits to plant species mixtures in terrestrial ecosystems

“…The decreased specific root length with species richness implied that fine roots reduced resource uptake efficiency in more diverse communities (Ostonen et al., 2007), which might have resulted from reduced soil resource competition due to the spatial and temporal complementarity between species (Barry, Mommer, et al., 2019). This lower interspecific competition for resources might be also attributed to more nutrient‐rich soil through more rapid litter decomposition in species‐rich mixtures (Liu et al., 2020). The lack of species richness effects on root length density 'may be primarily attributable to the limited range of species richness (2 and 3) in our meta‐data (Figure 2b).…”

“…This finding was in contrast with the prediction of the stress gradient hypothesis, which posits that diversity effects increase with environmental harshness. Although interspecific facilitation may be enhanced under resource limitations (Forrester & Bauhus, 2016; Maestre et al., 2009), it is possible that the increased availability of water and nutrients with accelerated litter decay rate augmented niche differentiation under humid conditions (Liu et al., 2020). The enhanced effects of species mixtures on root biomass with higher water availability in more diverse communities might also be attributable to stronger resource partitioning in resource‐rich environments.…”

Global negative effects of nutrient enrichment on arbuscular mycorrhizal fungi, plant diversity and ecosystem multifunctionality

“…For AMF Shannon index, we found no significant log e () ~ log e (SD) relationship. We thus estimated the missing SD by multiplying the average coefficient of variation by the reported mean value (Wiebe et al ., 2006; Bai et al ., 2019; Liu et al ., 2020). The percentage of missing SD for each variable is listed in Table S1.…”

Perennial Trees Associating with Nitrogen-Fixing Symbionts Differ in Leaf After-Life Nitrogen and Carbon Release

“…The three species occur in the same locality on Guam today, S. nelsonii and I. bijuga occur in the same localities on Rota, and C. micronesica and I. bijuga occur in the same localities on Rota (personal observations). Single species litter that is decomposed in isolation often does not correlate with decomposition of multi-species litter mixtures [54][55][56]. Litter species mixture phenomena remain to be studied for these three Guam trees and the other sympatric tree species that share the forests.…”